The present invention relates to improvements in repeater cases and designs therefore for high-density subscriber lines. Repeater cases have been known for years, and the technology was well developed for T1 telecommunication lines. Extensive specifications for 818-/819-type repeater cases have been promulgated by AT&T describing the type of cases involved. These cases are designed to hold sensitive telecommunications equipment in relatively unfavorable environments. In particular, they are designed for installation in manholes or on telephone poles exposed to the weather. Accordingly, in order to protect the contents, the housings of the cases provide environmental protection and seal the contents from attack by environmental elements such as water and the like.
Recently, the repeater cases which were originally designed to hold T1 line cards have been used to hold high-density subscriber line modules. The high-density subscriber line modules are somewhat larger than T1 modules, resulting in only every other one of the slots provided in the T1 case being used for the high-density subscriber line modules (hereinafter referred to as "HDSL modules").
The HDSL modules work well in the T1 repeater cases, except that it has been found that the modules prematurely fail due to excessive heat buildup. Premature failure adds considerably to the cost in having to replace the modules, with costs coming from the modules themselves, as well as the labor to get into the casing to replace the modules. There is also the problem of loss of reliability arising from the premature failures. Accordingly, there is a need in the art for a solution to the heat buildup problem in high-density subscriber line cases.